Dynamic cluster isolation

Use dynamic cluster isolation to isolate applications from other applications that are deployed in the cell. For example, you might create a dynamic cluster isolation configuration to isolate the critical applications that an external customer uses from the internal applications, which can tolerate some instability.


Scenario

Your company hosts Web applications for external customers and for internal departments in the company. To provide the most stable and secure service for the external customers, to be sure that their applications run on separate computers. Your hosting environment must adhere to the following requirements:


Solution

Use dynamic cluster isolation to meet the requirements of the customers. Dynamic cluster isolation specifies whether the dynamic cluster runs on the same nodes as other instances of dynamic clusters, or whether the dynamic cluster is the only dynamic cluster running on a node. The following configurations meet our customer requirements:

By configuring the dynamic cluster with specific isolation requirements, you are providing the most stable and secure service for customers while also hosting internal applications for the company.


Priority of isolated dynamic clusters

Dynamic cluster isolation ensures that dynamic cluster instances from different dynamic clusters do not run on the same node, but it does not make guarantees about how the system avoids a violation of the isolation mode. Configuring strict isolation does not give a dynamic cluster priority over any other dynamic clusters.

For example, we might have an environment with one available node, and two dynamic clusters. Each dynamic cluster has the minimum number of cluster instances set to 1. Consider the following isolation configuration scenarios:

In both of these scenarios, the application placement controller can place a single cluster instance for one of the dynamic clusters. Dynamic cluster instances cannot be placed for both dynamic clusters because only one node is available. In both scenarios, no guarantee is made about which dynamic cluster starts an instance. Even in the second scenario, where one of the dynamic clusters has strict isolation defined, the isolated dynamic cluster does not have priority over the other dynamic cluster. This restriction can be problematic for small systems, such as a single node environment, or environments with a large number of constraints.


Related concepts

  • Dynamic clusters


    Related tasks

  • Create dynamic clusters

  • Intelligent Management: dynamic cluster administrative tasks